Dick, lullabyes consisting entirely of rests have been tried many times over the ages, but they just don't work -- at least not for babies. For adults, they might.Somebody made a comment on a different thread that lullabyes are too short. Little did she suspect! What you have to do is start singing in a normal voice, then repeat the song as many times as needed, each time a little softer. Finally the kid slips off into sleep.
I remember my mother doing that with my nephew. He was staying at Grandma's incident to the birth of a little sister, and he couldn't go to sleep in a strange room with his mother nowhere around! So my mother sang "Pony Boy" over and over and over. And each time she finished, he gave a little tug to her sleeve to make her sing it again,until finally...